“It’s an obvious waste of building space, to use such high shafts for only one cabin,” he said. “It’s like operating one train between two cities on one track, instead of multiple trains on flexible tracks.”

In June, the company unveiled the first functioning model of the elevator, called Multi, at its test facility in Germany. As CityLab notes, Thyssenkrupp has been trialing the system at the 807-foot-tall concrete test tower since late 2015.

The elevator cabins propel themselves by maglev, or magnets that levitate and move by repulsion. Instead of cables, each cabin has one motor that kickstarts the maglev — the same technology behind the Shinkansen, Japan’s bullet train.

The goal of the Multi is to make transport within tall buildings, like skyscrapers, more efficient, Schierenbeck said.

Its shafts are 25% smaller than normal elevators, creating more room for a building’s floor space to be used for other things, like offices and apartments. Since multiple elevators can loop simultaneously in the same shaft system, the Multi can transport 50% more people in the same time as an average elevator — even at just 11 mph.

For comparison, the elevator in New York City’s Empire State Building travels at around 22 mph. The Shanghai Tower in Tokyo (completed in late 2016) has the fastest elevator in the world at nearly 46 mph.

While the Multi is slower than these, users won’t need to wait more than 30 seconds for an elevator to arrive, Schierenbeck said. There are no concrete plans on where the Multi will appear first. But when the Capital Market Authority Tower in Riyadh, Saudi Arabia opens in 2018, it will include Thyssenkrupp’s TWIN elevator system, which fits two cabins in one hoistway.

Beyond skyscrapers, the elevator system could be helpful in other busy places, like large malls and airports. Space limitations in already-crowded cities means there’s nowhere to go but up.